The first time we get Fastq.item and the second time we get Biocaml_fastq.item. The latter style then remains for all subsequent invocations. It is not necessary to call the same function both times. The style changes permanently regardless of what value is being executed.

Maybe of relevance: the Biocaml module is a manual pack, i.e. it contains definitions like `module Fastq = Biocaml_fastq". I do not see the above behavior in Core, which uses -pack.